结构钢刻痕杆断裂试验  

Fracture experiment of structural steel notched bars

作　　者：王万祯[1] 李松[1] 赵少俊[2] 张建军[1] 

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050 [2]兰州理工大学理学院,甘肃兰州730050

出　　处：《兰州理工大学学报》2008年第3期131-134,共4页Journal of Lanzhou University of Technology

基　　金：甘肃省自然科学基金(3ZS051-A25-044)

摘　　要：为研究结构钢断裂机理及抗断设防,对10个结构钢刻痕杆进行断裂试验,试验较为精确地记录了全程载荷-位移曲线和断裂载荷.试验结果表明,塑性变形只发生在刻槽处很小的范围内,lüders带局部区域的传播导致屈服平台不明显;初始裂纹始于颈缩中心部位的夹杂物或硬相粒子处,微孔的增长和合并导致延性断裂,试件最终断裂于应力三轴比率和等效应变都较高的刻痕根部,其断裂形式为正断与剪断混合型,断口为杯锥形,显示了断裂的定性规律.试验数据离散较小,试验结果与预测一致,为研究结构钢断裂机理及抗断理论提供了可靠的试验数据.To study rupture mechanism and fracture design of structural steel, fracture experiments were conducted with 10 notched bars of structural steel. Complete load vs displacement curves and fracture loads were accurately recorded. Experimental results indicated that plastic deformation occurred only within a small region of the notch and yield point elongation was unconspicuous, ductile fracture was governed by void growth and coalescence, the crack was initiated at the center of notched section containing inclusion or hard particle; and the fracture of the notched bar took place at last in notched section with greater triaxiality of stress and equivalent strain. Fracture mode was combined shear and normal fracture and the fracture section took the form of conic cup. The experimental data were stable and qualitatively revealed fracture rules. Good correlation between experiment and prediction were achieved, providing reliable experimental data for investigating rupture mechanism and fracture design theory of structural steel.

关 键 词：结构钢 断裂机理 初始裂纹 应力三轴比率 等效应变 混合断裂 

分 类 号：TB302[一般工业技术—材料科学与工程] TU391[建筑科学—结构工程]